1. Field of the Invention
The present invention relates to joints of Ti--Al intermetallic compounds adapted for components of various apparatuses, fireproof constructions, springs for high-temperature use, etc., and a method for manufacturing the same.
2. Description of the Related Art
Ti--Al intermetallic compounds are promising materials that have outstanding properties, such as high resistance to heat, acid, wear, etc. and light weight, and can, therefore, be used in various applications. Typical products that are expected to utilize the intermetallic compounds of this type include outer wall materials, turbine components, and engine components, such as pistons and valve systems.
A structure that includes lamellae is known as a mode of a Ti--Al intermetallic compound. A Ti--Al lamella is a layered structure in which sheetlike grains composed mainly of gamma phases (TiAl) and ones composed mainly of .alpha..sub.2 phases (Ti.sub.3 Al) are substantially alternately arranged in layers, and is very strong. The inventors hereof formerly disclosed high-strength Ti--Al intermetallic compounds and a manufacturing method therefor, in Jpn. Pat. Appln. KOKAI Publication Nos. 6-172899 and 6-264203. In these prior art intermetallic compounds, adjacent lamellar grains are coupled directly to one another without any other continuous phases interposed between them.
In some cases, the manufacturing costs of products that are composed of the Ti--Al intermetallic compounds can be lowered by forming each product from a plurality of separately manufactured components, which are bonded together when the product is to be completed. If two base members that are composed of Ti--Al intermetallic compounds are bonded together by means of conventional diffused junctions, however, the junctions inevitably constitute mechanically weak points.